Adi Sumarmo International Airport, abbreviated as BIAS, played a central role in the multimodal transportation system in Central Java Province, Indonesia. On this basis, this study investigated the service quality of multimodal transportation in BIAS using the importance-performance analysis (IPA). This study measured 13 variables of multimodal services based on the level of performance and importance. The results revealed that currently, there has been an effective multimodal transportation services in supporting passenger mobility in BIAS, with an average score of 3.43. Meanwhile, respondents' assessment on the level of importance of all variables showed an average score of 4.36. From 13 variables of multimodal transportation services, the following three variables need to be prioritized to support efforts to increase service effectiveness: travel time, variety of transportation modes for other trips, and shelter facilities. This paper emphasizes the need to improve the existing multimodal transportation services in BIAS to meet user expectations.